Thermo-electric indicator and safety device



March'l5 192 7 w. A. COLLINS TKERMO ELECTRIC INDICATOR AND. SAFETY DEVICE 2 Shouts-Sheot Filed April 19, 1923 ATTO RN EYS March W. A. COLLINS THERMO ELECTRIC INDICATOR AND SAFETY DEVICE Filed Apx il 19, 1923 2 Shoots-Shoot 2 INVENTOR 9 WILL/4M F7- COLLINS I BY 70 to carburebr ATTORNEY Patented Map 1 5,

UNITED 1 "PA -Eur .o FIcE.

wmmnr a; corms. or rmannrrnm, rnxnsnvanm, assreuomjir Irena momma, To run sun-'r-s'ra'r co., or rmnannnrnm, rnmwsrnvanu, a

coarona'non or nmwm;

'rnzmro-nm craro mmca'ron mm mm! Davies. 1

a lication fled 1pm 19, 192:. serial No. 833,315.

My invention relates to an improved temperature indicator and safety device. While specifically applicable to explosion engine's, its utility is not limited to this type of 6 installation.

Amon the objects (if my invention may be sp'eci ed first, the provision of a temperature indicator actuated by an electrical heating resistance, the circuit of which is governed by a thermostat subject to temperature fluctuations; second, the provision of means alsogoverned by the thermostat for controlling the source of temperature fluctuations; third, various details of specific construction and application hereinafter described or shown in the accompanying drawings, in which a ig. 1 is a more or less diagrammatic side elevation oi an explosion engine to, which my invention is applied in one form v Fig. 2 is a verticalsection, on a larger scale, .through the indicator; Fig. 3 is a front elevation of the latter; Fig. 4'is a section onthe line 44, Fig. 2;

Fig. 5 is a broken plan view of the thermostatic element and its mounting;

Figs. 6 and 7 are, respectively, sections on the lines and 7-7, Fig, 5;

- Fig; 8 is an inverted plan of the thermo static element detached; and

Fig. 9 is a diagrammatic scheme .ofthe layout, illustrating, however, a different type of engine cut-out from that shown in Fig. 1. As above stated, the presentinvention is- 'more broadly applicable than to an ex 10- sion engine. It is therefore only to i vustrate the invention and one practical application thereof, that I have shown it associated with an explosion engine .of. usual t for automobiles. eferring to Fig. 1, the explosion engine 10, of anyappropriate jacketedtype is provided with an outlet ipe 11 for the temperature exchan e flui which will for convenience be ca led water, leading to' the radiator 12. The pipe is connected to they dome 13, at which point the water is at its highest temperature and passesthence immediately through the pipe 11 to the radiator for cooling. As is well known,.the engine functions to best advantage when quite warm, but disadvantageous conditions occur if its I temperature rises above a certain point. Inasmuch as the engine temperatureis reflected by the temperature of the water, an indication of the latter affords a safe indication of engine conditions. i v

To obtain such indication I provide a thermometer 14, preferably of the s irit type, mounted in a suitable casing. 15 o the dash 16 of the car at a point readil visible to the operator. To actuate the t erinometer, its bulb 17 is surrounded by a resistance coil 18, the current flowing through which is controlled by a thermostatic switch, generally indicated in Fig. 1 by the reference 19, and the circuit being established from any suitable source 20 through the resistance coil 18 and"lead 21 to .the switc 19 and thence to ground. It may be briefl stated that by"means hereinafter described, the thermostatic switch controls the current passing through the heating coil 18' in 'such fashion that as the temperature of the water in the engine jacket rises, more current flows through the coil 18 and the bulb 17 of the thermometer is heated with consequent indication of temperature by the rise of the liquid in the stem of the thermometer.

The second phase of the invention-viz the thermostatic control of the source of temperature fluctuations-(i. e., the engine,

in this case) is also enerally indicated in Fig. 1. To this end,-t e thermostatic switch has connected thereto, a lead 22 to the spark circuit of the engine-for instance, to the "ma etc 23. When the thermostat has. been suciently distortedby the heat of the water from the engine jacket, this circuit is closed and the magneto grounded, thus cutting out the sparking system and halting the engine 'until the water has cooled ,sufiicient-ly to again open'the ground connection.

Turning to the details of construction, the thermostat is shown on a large scale'in' Fig. 58" inclusive. It comprises a, bi-metal spiral '24 carried by. a central mounting screw 25. The latter'is shouldered to bear a ainst' the insulatin base '26, through w ich itsthreaded en passes for engagement by the clamping nut .27 The outer free end of the spiral forms a brush 28, which, ,on the distortion of the thermostat Y by ='.heat, successively wipes the switch'contacts 29, 30 and '31 in the circuit of the heatin coil18, and eventually engages the groun ing contact .32 of the magneto 23. Interposed between switch contacts 29 and 30 is a resistance 33, 'while between contacts 3 andY31-isa second resistance 34. The, lead 21 fromthe heating coil 18 is connected to the binding post 35 associated with switch contact 31, so. that when the brush'28, following initial distortion of the thermostat, engages contact 29, the current fiov? to the heating coil 18 is cut down by both resist- 7 ances 33 and 34 in series. When the brush engages contact '30, the resistance 33 is cut outand more current passes to. the heating coilsuflicient"to cause the indicating spirit to rise to the level of the-legend Normal.

' When the engine becomes overheated, the:

thermostat brush engages'contact 31,'cut

ting out htoh resistances 33 and 34, thus --.permitting the flow of full current to the heating coil 18 and causing arise of the indicator spirit to the level of the legend Danger. If this Warning is not heeded, and the engine is continued in operation,

I until the heat of the water -infits jacket causes the thermostat brush 28 to engage contact 32-, the magneto is short-circuited'- and the engine automatically stopped by the cessation of the ignition spark. 1 A convenient mounting of the resistances 33jand 34 is indicated. The resistance wire 7 is'wound on independent flattened cardboard spools, which are. passed over a bar 36 of fiber insulation. The ends'37 and 38 of the resistance wire, as well astheintermediate loop 39 between the -spools, are clamped by the spun-over rivet heads of bushings'40 carried b the bar 36. The bushings are alsoshou dered to engage the bases of the met-a1 yoke 42, the arms 43 and'44 ofwhich embrace the pipe and are provided adjacent their free ends with series of apertures 45. to receive a draw-up .bolt 46-and by r2 8, on overheating of the. thermostat, en-

which the appliance may be secured to pipes of diflerent diameters. The yoke is secured to the casing by lugs. 47 struck out from the'casing side walls and passing through a propriate o enings in thearms 43 and, 44 o the yoke. his construction also serves to hold the base 26' andcasing assembled prior to mounting-on the pi e 11. In mounted position, the inner en of the thermostat i 7 post 25., or a contact lug 48 thereon, is

pressed against thepipe 11 and aflords the grounding connection for the circuit through the switch. The m'agneto cut-out contact 'is mounted on,'bu t'in 1 t d, m the easing wall 41. It may, for example, be clamped beneath the head of the binding post '49 which is spaced by appropriate inand holdsthe'mount agalnst rotation. \Vith- .in the boss 51 is arranged an insulating plug preferably of fiber or thelike, recessed at oneend to receive the heating coil 18 a and having independent passages extending to its opposite end .to receive the connector,

terminals 56 to which the opposite ends of the coil are respectively soldered. Set screws 57 passing through the walls of the plug andof the connectors, serve'not only to hold the latter in position on the lug, but also to secure the ends of the lea s 20 and 2].. The offset, bulb end 17 of the .thermonieter is accommodated withinthe.

coil 18 and is supported and positioned by means of a washer 58 fittingwithin the end of the plug 55. 'A clip 59 grips the upper end of the thermometer stem. It will be noted that the bulb 17 is practically enclosed within the plug chamber which accomm'odates the heating coil 18, and that the heat of the latter is thus effectively confined and transmitted to the liquid in the bulb.

Facing the stem of the thermometer is the legend carrier 60, centrally apertured to pera the liquid level with respect to the legends 61. The cover plate and guard 62 is secured by screws. 63 to the base plate-50 and confines and supports the legend carrier, which is visible through the opening 64'there1n.

In its main features the modification illus-v trated .in'Fig. 9 is the same as that. above described. Instead of grounding the magneto through the thermostat, however, the device serves tocut- 0d the fuel supply under the samev conditions, .Thus, when. the brush gages contact 32, a circuit is closed through an electromagnet 65. Thecoil is wound on a soft iron core, the head 66 of whichyispressed to form a passa eway 67.- It: is j threaded at one end 68-to orm a nipple for I attachment-in the fuel. supply line--(e.. g.,

just below the vacuum tank) and at its other end 69 toform a nipple on which-l2"5 screws a brassflv'alve chamber -70',in. turn 'mit inspection ofthe stem and the riseof threaded .at, 71 for the pipe connectionfto the carburetor..- A stee ball-72 arranged inthe valve chamber normally occupies an openvalve position. When-the coil is ener-' gized, howeverfthe ball is attracted to its seat 73 and closes the passage 67, thus cutting oil the flow of fuel t9 the carburetor so long as the coil 65 remains energized.

'ThiS construction has a" certain advantage overthe construction first described, in that a motor the cylinders of which are carbonized, is not effectively stopped by cutting out the ignition, since the red hot carbon in'the cylinders ignites the charge. of fuel is cut ofi, however,--as bythe present arrangement,this possibility is, obviated.

It will be observed thatjthe only mutilm,

which do not depart from what I claim as my invention. Moreover, .the adaptation of the underlying thoughts, not only to other types of explosion engines, but also to other types of temperature indication and icontrol,e. g., refrigerators-is within the scope. 0t what I claim as my invention.

I claim- 1. In a temperature mdlcator, the combination with a visible indicator element consisting of a liquid column thermometer, of a heating resistance placed in proximity If the supply cult includin It is efiective in service I thereto to affect the liquid column, an elecv tric circuit including said resistance, and a thermostatic rheostat controlling the current in said circuit.

2. In a temperature indicator, the combination with a visible indicator element consisting of a liquid column thermometer, of a heating resistance placed in proximity thereto to affect the. liquld column, and electriccircuit including said heating resistance together with a plurality of additional resistance units, and a thermostatic switch arm adapted with increasing temperature to progressively out said units out of circuit.

3. The combination with an internal combustion engine, of a rheostat including means controlled by the temperature of the engine, a heating resistance, an electric cirsaid resistance and said rheostat, and a vlsible indicator consisting-of a liquid column thermometer placed in proiimity to and to be-afiected by said resistance."

4. The combination with an internal coins bustion engine, of an electric circuit including a rheostat anda heating resistance, thermo'static means for operating the rheostat in accordance with the engine temperature whereby as the .said temperature increases rheostat resistance is progressively cut out of the circuit, and a visible indicator consisti-n of a li uid column thermometer placed in proximity to and to be affected by said heating resistance.

, In testimony whereof I have signed my name to this specification.

WILLIAM, A. COLLINS. 

